Foldases Catalyzing the Formation and Isomerization of Disulfide Bonds in Proteins

Description for Foldases Catalyzing the Formation and Isomerization of Disulfide Bonds in Proteins

Click to show screenshot
Natalya K. Nagradova, quot;Foldases Catalyzing the Formation and Isomerization of Disulfide Bonds in Proteinsquot;
Nova Science Publishers Inc | 2009-04-01 | ISBN: 1606924664 | 75 pages | PDF | 1,2 MB
One of the rate-limiting steps in the folding pathways of many secretory proteins is the formation of correct disulfide bonds between cysteine residues. In eukaryotes, both disulfide bond formation and isomerisation which shuffles incorrectly formed disulfides are catalysed by protein disulfide isomerase (PDI), whereas in bacteria these two reactions are catalysed by separate enzymes. Both in eukaryotic and prokaryotic cells the oxidation and isomerisation steps proceed exclusively in extracytoplasmic environments (the lumen of the eukaryotic endoplasmic reticulum and the Gram-negative bacterial periplasmic space). The family of foldases under discussion is characterised by a conserved 'thioredoxin fold' and a common active site motif: Cys-X-X-Cys. The process of disulfide bond formation relies on thiol-disulfide exchange between oxidised and reduced cysteine pairs in the catalyst and substrate protein. Two separate pathways involved in disulfide bond formation and isomerisation have been characterised both in eukaryotes and in bacteria. In the oxidative pathway, oxidizing equivalents flow from oxygen to a membrane protein (Ero1p in eukaryotes or DsbB in bacteria), and then to a folding protein containing reduced cysteines via PDI (in eukaryotes) or via DsbA (in bacteria). In the isomerisation pathway, DsbC (bacterial protein disulfide isomerase) or PDI (in eukaryotes) interacts with substrate proteins that contain non-native disulfide bonds, allowing these bonds to rearrange to their native pairings. Reducing equivalents which are necessary to maintain DsbC in a reduced form, able to attack misfolded disulfides, are transferred from the cytoplasm with the aid of the cytoplasmic membrane protein DsbD. In eukaryotes, reduced glutathione is the main source of reducing equivalents for PDI. A dual role of PDI as an oxidase and an isomerase is facilitated by its complex domain architecture.

Enjoy this great book! Brought to you by SMIRK

Uploading


DepositFiles


My AH blog!


mirror


!!! !!!

Foldases Catalyzing the Formation and Isomerization of Disulfide Bonds in Proteins.full.rar

Foldases Catalyzing the Formation and Isomerization of Disulfide Bonds in Proteins [TRUSTED HIGH SPEED DOWNLOAD]

Search

1. Rapidshare video-audio list page : 1866
2. Catalyzing Inquiry at the Interface of Computing and Biology
3. The Role of Theory in Advancing 21st Century Biology: Catalyzing Transformative Research
4. Peptides and Proteins
5. Private Sector Finance: Catalyzing Private Investment in the Asia and Pacific Region
6. Glycosylphosphatidylinositol (GPI) Anchoring of Proteins
7. Complement Regulatory Proteins
8. Amanda Rondeau - Proteins Are Powerful
9. The Gluten Proteins (Special Publication)
10. Bernhard Krautler - Vitamin B12 and B12-Proteins
11. Proteins: Structure and Function (repost)
12. Vectorial Transport of Proteins into and across Membranes
13. HIV Interactions with Host Cell Proteins
14. Heat Shock Proteins in Myocardial Protection
15. Thermodynamics of Solutions: From Gases to Pharmaceutics to Proteins
16. Manufacturing of Pharmaceutical Proteins: From Technology to Economy